Work tower for relining metallurgical vessels

ABSTRACT

An apparatus for lining the walls of a metallurgical vessel with refractory bricks including support means over the top opening of the vessel, elongated tower means suspended within the vessel from the support means and rotatably movable thereon, and first conveyor means, in the tower and rotatably movable therewith, for conveying bricks vertically within the vessel. The first conveyor means has a charging end, and a discharge point which is vertically variable. A second conveyor means is provided which is vertically movable on the tower means and has a discharge end laterally adjustable with respect to the tower means. The second conveyor means receives bricks from the first conveyor means and transports them to the walls of the vessel at variable heights and distances from the tower means. By reason of the vertically variable discharge point, the first conveyor means delivers bricks to the second conveyor means at any position of the second conveyor means.

United States Patent Gregord et al.

[ June 10, 1975 Primary ExaminerErncst R. Purser Assistant ExuminerCarlD. Friedman Almrney, Agent, or Firm-Parmelee Miller, Welsh & Kratz [57]ABSTRACT An apparatus for lining the walls of a metallurgical vesselwith refractory bricks including support means over the top opening ofthe vessel. elongated tower means suspended within the vessel from thesupport means and rotatably movable thereon, and first conveyor means inthe tower and rotatably movable therewith for conveying bricksvertically within the vessel. The first conveyor means has a chargingend, and a discharge point which is vertically variable. A secondconveyor means is provided which is vertically movable on the towermeans and has a discharge end laterally adjustable with respect to thetower means. The second conveyor means receives bricks from the firstconveyor means and transports them to the walls of the vessel atvariable heights and distances from the tower means. By reason of thevertically variable discharge point the first conveyor means deliversbricks to the second conveyor means at any position of the secondconveyor means.

16 Claims, 12 Drawing Figures PATENTEUJUH I 0 I975 PATENTEDJUN 10 ms .1

SHEET 2 FIG. 3.

PATENTEBJUHIU I975 3,868,062

SHEE? 4 FIG. 5.

PATENTED JUN 1 U I975 SHEE? ban.

1F EFF HIE IF '5' .51 Eli RE-EROS? PATENTEDJUH 10 I975 SHEEE WORK TOWERFOR RELINING METALLURGICAL VESSELS BACKGROUND OF THE INVENTION I. Fieldof the Invention:

This invention relates generally to work towers for relining the wallsof metallurgical vessels. such as L-D furnaces, ladlcs and the like. andmore particularly to work towers for relining such vessels havingconveyor means for transporting refractory bricks to selected locationsat the vessel walls.

27 Prior Art In the steelmaking industry the most efficient method ofmanufacturing steel is the basic oxygen process. In that process. acharge of molten pig iron, scrap and additives such as slugging agentsin an open-top converter is subjected to a supersonic stream of highpurity oxygen from a lance lowered through the vessels top opening, andis thereby blown to steel. The basic oxygen process is highly corrosiveto the steelmaking vessel's refractory lining, and in a typical shop itis usually necessary to reline a vessels walls after about 2 weeks use.The relining operation is a slow, costly process, generally requiringthe use of It) or more men for several days. It has been necessary inthe past to construct a scaffold and lay-up the refractory brick coursesby hand. Some more automated versions of work towers have also beenproposed which include elevators and the like, but these have not provenpractical or gained industry acceptance. The present invention providesan apparatus for relining a metallurgical vessel at a reduced expense oftime and labor then has heretofore been known, and reduces to a minimummanhandling of the refractory brick used in lining the vessels walls.

SUMMARY OF THE INVENTION An elongated tower is provided which is adaptedto be suspended within a metallurgical vessel from a support centeredover and above the vessels top opening. Means are provided for rotatingthe tower on its support and within the vessel. and a first conveyormeans is located in the tower for transporting refractory bricksvertically to any desired depth in the vessel. A second conveyor meansis provided which is vertically movable on the tower means and has adischarge end laterally adjustable with respect to the tower means. Thesecond conveyor means receives bricks from the first conveyor means. andtransports them to the walls of the vessel at variable heights anddistances from the tower means. The first conveyor means has a chargingend and a discharge point. and the discharge point is verticallyvariable so that the conveyor means delivers bricks to the secondconveyor means at any position of the second conveyor means.

A rotating feed table may be provided for feeding bricks to the chargingend of the first conveyor means. This feed table is adapted to rotateabout the tower at a speed of rotation greater than the speed ofrotation of the tower. The feed table comprises a series of radial traysdisposed at an angle above the horizontal, and interconnected in ringform. These trays have rollers which urge bricks on the trays in adirection generally toward the first conveyor means.

A platform means may be provided which mounts on the elongated towermeans and is vertically movable thereon. The movement of the platformmeans may be either independent of or conjoint with a second conveyormeans. A support for workmen is therefore provided corresponding to theheight of the second conveyor means.

DESCRIPTION OF THE DRAWINGS FIG. I is a sectional elevation showing oneembodiment of the relining apparatus of the present invention in workingposition in an open top metallurgical vessel with the second conveyormeans and work platform shown in various positins in which they may belocated.

FIG. 2 is an elevation view of the second conveyor means in fullextended position and the discharge point of the first conveyor means.

FIG. 3 is a sectional elevation view taken along the line III-III ofFIG. 2.

FIG. 4 is a sectional plan view taken along line IVIV of FIG. 2 with thesecond conveyor means shown fully retracted, and also shown in phantomfully extended.

FIG. 5 is a plan view of the platform means and second conveyor means ofthe present invention.

FIG. 6 is plan view of the rotating feed table and feed conveyor of thepresent invention.

FIG. 7 is a perspective view of a portion of the chains of the firstconveyor of the present invention, showing the U-shaped links and novelsprockets of the inner chain.

FIG. 8 is a plan view of the feed conveyor, control conveyor and sensingmeans for the present invention, showing one rotary feed table tray inposition for sens ing for the presence of a brick on that tray.

FIG. 9 is a side elevation view of the apparatus shown in FIG. 8.

FIG. 10 is a plan view of a portion of the rotary feed table of thepresent invention, showning two traps of the table.

FIG. 11 is a sectional side elevation view of the control conveyor ofthe present invention.

FIG. 12 is a diagrammatic view of the first sensor of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thefigures. in FIG. I the preferred embodiment of the relining apparatus ofthe present in vention. designated generally 2, is shown in workingposition in an open-top metallurgical vessel 4, such as a basic oxygenfurnace. The relining apparatus includes an elongated tower portion 6having frame members 8, l0, l2 and 14 and cross members 16. Theelongated tower 6 is suspended within the vessel 4 from supports 18which rest on service floor 20. In operation, supports 18 are positionedsuch that the tower, when suspended therefrom, is generally centeredwithin vessel 4.

Frame members 8, I0, 12 and 14 of the elongated tower 6 are rotatablyinterconnected with supports 18 whereby tower 6 may be rotated onsupports 18, and hence rotated within vessel 4. The tower 6 and thesupports 18 are interconnected through a large diameter ball bearingring 22. Ball bearing ring 22 is large and strong enough to support theapparatus without the use of a stabilizer on the vessel bottom. Drivemeans, such as motor 24, is fixedly or rigidly attached to a framemember of the elongated tower 6. Motor 24 is operably attached to adrive train such that activation of motor 24 causes rotation ofelongated tower 6 of apparatus 2.

A first conveyor 26 is provided within the elongated tower 6 forconveying bricks from the surface floor to selected locations withinvessel 4. Preferably, the first conveyor 26 comprises two pairs ofendless chains 28 and 30 (only one of each pair appears in the elevationview of FIG. I). Chains 30 follow a path defined by sprockets 3]attached to fixed shafts 32, 34 and 36 and also be sprockets 31 attachedto shafts 38, 40 and 42 which are attached to movable frame 44. Chains28 follow a path defined by sprockets 33 on fixed shafts 32 and 34 andalso sprockets 33 on shafts 40, 42 and 45, also on movable frame 44.Pairs of endless chains 28 and 30 travel in substantially the samedirection along the path defined by these sprockets. Therefore, in theportion of the path of travel which is above the movable frame 44, pair28 travels in a plane parallel to and disposed from the plane of travelof the other pair 30, and below the movable frame 44 the pairs of chains28 and 30 travel in the same plane.

Foldable platforms or pallets 46 are each connected to both pairs ofchains 28 and 30 by rods 51 at spaced intervals along the chains. Duringthe portion of the descending path of travel of the chains when they areabove the movable frame 44 and are spaced away from each other, foldablepallets 46 are suspended by the rods 51 between the pairs of chains 28and 30 in a horizontal position, and form rigid pallets which supportrefractory bricks. During the portion of travel of the chain below themovable frame 44, and also during the ascending path of travel, thesefoldable pallets 46 are suspended vertically between and in the sameplane as the pairs of chains 28 and 30.

Foldable pallets 46 are each attached at one end to inner chain pair 28,and at the other end to outer chain pair 30 (FIG. 7). Since the chains28 and 30 travel in the same plane over a portion of their path oftravel, U- shaped links 47 are provided at the points on inner chains 28corresponding to the points where the foldable pallets 46 are connectedto the outer chains 30. The sprockets 31 on which chains 28 travel aredesigned such that the teeth of the sprockets 31 only engage alternatelinks of chains 28. The U-shaped links 47 are so arranged on the chains28 as to always fall between the teeth on the sprockets 31. Thus therods 51 connecting the foldable pallets 46 and outer chains 30 do notinterfere with the engagement ofinner chains 28 by sprockets 31.

As shown in FIG. 2, movable frame 44 is supported by cables 49 whichpass through sheaves 50 and are attached to hoists 52. By the winding orunwinding of cables 49 on hoist 52, movable frame 44 may be raised orlowered along tower 6.

A second conveyor 54 is attached to the movable frame 44. Secondconveyor 54 includes an endless belt 56 which travels around fixedrollers 58, 60 and 62 and movable rollers 64, 66 and 68. By manualoperation of a crank 69, movable rollers 64, 66 and 68 can behorizontally adjusted so as to change their distance from tower 6, andthereby change the length of the upper surface of the belt 56.

From the above description of the structure of first conveyor 26 andsecond conveyor 54, the operation of these conveyors becomes apparent.Refractory bricks are loaded onto the upper, or charging, end of thefirst conveyor 26, and are carried downwardly by the foldable pallets46. Upon reaching the height of movable frame 44, the foldable pallets46 are moved horizontally by the movement of chain pairs 28 and 30around sprockets on shaft 40. Therefore a discharge point on the firstconveyor 26 is defined by the position of shaft 40. This discharge pointis vertically variable along the tower 6 according to the movement ofthe movable frame 44 and, since second conveyor 54 is attached tomovable frame 44, the discharge point of the first conveyor 26 willalways be proximate the second conveyor 54.

Shaft 40 and roller 58, both of which are rigidly fixed to movable frame44, are connected by a second conveyor drive means 70. This secondconveyor drive means 70 is preferably an endless chain which connectssprockets on shaft 40 and roller 58 and which causes movement of roller58 according to the movement of shaft 40. It can be seen that firstconveyor 26 and second conveyor 54 will move conjointly at proportionatespeeds. Therefore, upon movement of the foldable pallet 46 in ahorizontal direction toward the second conveyor 54, the refractorybricks are carried from first conveyor 26 onto second conveyor 54. Aspreviously described, the length of second conveyor 54 can be al teredby the movement of movable rollers 64, 66 and 68. Thus, the distancethat the bricks will be carried from the tower 6 can be varied accordingto the distacne of the walls of the vessel 4 from the tower 6.

A work platform designated generally 72 may be provided upon whichworksmen may stand during the relining operation. In a preferredembodiment, work platform 72 includes pivotally mounted support members74 (pivot means not shown) at the inner end thereof, which are foldableto a vertical position for passing through the top opening of vessel 4.Platform 72 also includes horizontal radially extending members 76 forsupporting a circular array of grating 78 or the like, to provide asurface upon which workmen may stand during the relining operation.Radially extending members 76 have a telescoping function, and therebyprovide support for a circular grating surface of variable diameter. Theplatform 72 is movable vertically within vessel 4 over frame members 8,10, 12, and 14 of the elongated tower 6. Platform 72 may be eitherrigidly affixed to the movable frame 44, whereby second conveyor 54 andwork platform 72 will move conjointly, or work platform 72 may be raisedor lowered independently of second conveyor 54 by hoist 52. Preferablyplatform 72 includes horizontally extending frame members 80 surroundingthe respective frame members of the elongated tower 6 in a sleeve-likeor collar-like fashion for slidably mounting and moving platform 72 toselective locations within vessel 4 on the elongated tower 6. Platform72 may be fixedly attached to selected locations on the tower 6, forexample by means of removable pins in openings provided in platformframe members 80 and tower frame members 8, l0, l2 and 14. When platform72 is moved vertically within the vessel, the pins are removed to bereplaced in the openings at the next selected location for the platform72 on the tower 6. Access to platform 72 is provided by a ladder 79,which is attached to the tower 6, and which provides access from ascaffold 81, suspended from support 18, to any part of the tower 6.Workmen entering the vessel 4 to install the bricks first climb downthrough the service floor 20 on a second ladder 83 to the scaffold 81and down the ladder 79 to the work platform 72.

Referring now to FIG. 6, refractory bricks are fed to a rotating feedtable, designated generally 82, from a position remote from the reliningapparatus 2, by con ventional means such as feed conveyor 84. Preferablythe bricks are fed to rotating feed table 82 in exactly the order inwhich they are to be laid along the vessel wall during the reliningprocess, i.e., bricks are programmed" to the relining apparatus.Rotating feed table 82 comprises a series or radial trays 86interconnected in ring form. Trays 86 are disposed at an angle above thehorizontal. and are preferably provided with gravity rollers 88., suchthat a brick, when placed upon tray 86, is urged in a directiongenerally towards the first conveyor 26. Feed table 82 generallysurrounds the elongated tower 6 and is adapted to rotate thereabout at aspeed of rotation greater than that of the tower. Rotation of feed table82 causes refractory bricks in the table to be carried in the directionindicated by the arrow in FIG. 6.

A raised circular shoulder means 90 is provided along the insidediameter or edge of radial trays 86 of rotating feed table 82. Theshoulder means 90 extends vertically about the edge of the tray 86 andis adapted to rotate along with elongated tower 6, for example, as bybeing rigidly affixed thereto. Raised shoulder 90 includes a guideportion 92 for directing the refractory bricks onto a pallet 46 of thefirst conveyor 26 for vertical transportation into vessel 4. As shown inFIG. 6, guide portion 92 of raised shoulder 90 comprises a guide way ordoor formed therein through which refractory bricks may pass. Aninclined plane 94 having bearings or rollers 96 therein is provided forreceiving bricks passing from feed table 82 and transporting them to thefirst conveyor 26. Thus, it can be seen that, as feed table 82 rotates,bricks are carried to the guide portion and passed therethrough to thefirst conveyor 26 for vertical descent to selected levels in vessel 4.Upon reaching the first conveyor discharge point, bricks are conveyedtoward the vessel wall by the second conveyor 54 to be placed inposition.

Preferably, sensing means are employed in conjunction with feed conveyor84 and the rotating feed table 82 to control the transfer of bricks fromthe feed conveyor 84 to rotating feed table 82. Such sensing means isshown in FIGS. 8-12. In the embodiment shown in these figures, the feedconveyor 84 comprises a tilted roller conveyor having centering guides85, on which conveyor the bricks are moved by gravity onto a controlconveyor 98. The control conveyor 98 in turn sequentially transfers thebricks to each tray 86 of the rotating feed table 82. Control conveyor98 includes powered rollers 100 which continuously rotate by motor meansin such a direction as to urge bricks toward the rotating feed table 82.Control conveyor 98 also includes free rollers 101 and liftable rollers102, the latter of which are jointly operated by a pneumatic cylinder104. When liftable rollers 102 are moved to their lower position bypneumatic cylinder I04, a brick situate on the control conveyor 98contacts powered rollers 100 and is urged onto the rotating feed table82. When liftable rollers I02 are moved to their upper position bypneumatic cylinder I04, a brick situate on the control conveyor 98 issupported by the liftable rollers 102 and does not engage poweredrollers 100. The brick resting on liftable rollers I02 will thus remainin this position until liftable rollers I02 are moved to their lowerposition by pneumatic cylinder I04 so that the brick engages poweredrollers 100 to be urged onto the rotating feed table 82.

The operation of pneumatic cylinder I04 is controlled by a first sensor106, such as one or more photoelectric cells. As the rotating feed table82 rotated, each tray 86 assumes a position under first sensor I06immediately prior to being aligned with control conveyor 98, as shown inFIG. 8. Mirrors I08 are located on each tray 86 so as to reflect thebeam of first sensor I06 when there is no brick on that tray (FIG. 12),in which case the first sensor 106 signals the pneumatic cylinder 104 tomove liftable rollers I02 to their lower position so that poweredrollers I00 will urge a brick on to that tray 86. If a brick is presenton tray 86, the first sensor I06 does not received light from the mirror108, and pneumatic cylinder I04 maintains liftable rollers 102 in theirupper position so that no brick will pass onto that tray. Thus, no brickwill pass onto the rotating feed table 82 if there is already a brick onthe tray 86 which is at a position proximate the control conveyor 98.

As shown in FIG. 10, each tray 86 has an associated gate 110. This gate110 is adapted to ride upon a cam means (not shown) associated withshoulder on tower 6. The gate 110 remains in an upper position blockingthe path of bricks whenever the guide portion 92 (FIG. 6) is not alignedwith that tray 86. When the tray 86 is aligned with the guide portion 92of the raised shoulder 90, the gate I10 will drop, due to spring biasingof the gate and the weight of the brick, thereby al lowing the brick topass through the guide portion 92 and onto the first conveyor 26. Ashutter 112 is attached to the gate 110 to block the mirrors 108 whenthe gate I10 is opened. Therefore, if the tray 86, the guide portion 92,and the control conveyor 98 are all aligned, and no brick is situate onthe tray 86, and with gate 110 in downward position, the shutter willblock the mirrors 108 so that the pneumatic cylinder 104 will not allowa brick to pass onto that tray 86 in order to prevent the directcharging of a brick from control conveyor 98, through guide portion 92,and onto first conveyor 26, which could result in misalignment thereofand possible jamming or breakage of a brick so fed.

A second sensor 114, such as a photoelectric cell is positioned adjacentthe control conveyor 98 and controls pneumatic cylinder I04 to theextent that, when a brick is discharged from control conveyor 98, withpneumatic cylinder 104 having lowered the liftable rollers 102, thesensor 114 will signal to actuate the pneumatic cylinder 104 so as toagain lift the rollers 102 to a position above power roller whereby afurther brick is gravity fed from feed conveyor 84 onto the controlconveyor 98, so as to rest upon liftable rollers 102 and be positionedfor feeding onto a subsequent tray 86.

There has been described a novel apparatus for lining the walls of ametallurgical vessel with refractory bricks. Bricks are fed to thevessel on a feed conveyor, and are intermittently transferred by acontrol conveyor from the feed conveyor to sequential trays of arotating feed table. The bricks are transferred from the rotating feedtable to a first conveyor traveling at proportionate speed. This firstconveyor carries the bricks to a discharge point where they aretransferred to a second conveyor which deposits them at predeterminedlocations on the walls of the vessel.

We claim:

I. In an apparatus for lining the walls of a metallurgical vessel withrefractory bricks which apparatus in eludes support means over the topopening of the vessel, elongated tower means suspended within the vesselfrom the support means and rotatably movable thereon. and first Conveyormeans in the tower and rotatably movable therewith. for conveying bricksvertically within the vessel. the improvement comprising:

a second conveyor means having a laterally extend ing brick conveyingupper surface of adjustable length yertically movable on the tower meansfor transporting bricks between the tower means and the walls of thevessel at variable heights and dis tances from the tower means; andwherein said first conveyor means comprises:

a plurality of sprockets:

two pairs of endless chains traveling in the same direction on a pathdefined by the sprockets, which path has two vertical runs between upperand lower sprockets rotatably mounted at fixed positions on the tower,one said vertical run having a first portion in which one pair of chainstravels in a plane parallel to, and laterally disposed from, the planeof travel of the other pair, and a second vertical portion in which thepairs of chains travel in the same plane. the other vertical run havingthe pairs of chains travel in the same plane throughout the run;

a plurality of foldable pallets each of which is connected to both pairsof chains at spaced intervals along the chains. which pallets arehorizontally sus pended between the chains during the first portion ofsaid one vertical run, and are disposed in the same plane as the pairsof chains during the second portion of said one vertical run andthroughout the second vertical run; and

a frame having a plurality of sprockets rotatably mounted and arrangedthereon to guide one of said pairs of chains along a substantiallyhorizontal path between the two laterally displaced planes of the firstportion and the common plane of the second portion of said one verticalrun which imparts substantial horizontal movement to the foldablepallets as they pass from said first to second portion of said onevertical run. said frame being vertically movable on the tower to varythe respective lengths of said first and second portions of said one runand to align the horizontally moving foldable pallets between said firstand second portions in brick transferring relationship with the secondconveyor whereby bricks are conveyed between the exterior of themetallurgical vessel and the interior walls thereof through verticalmovement by said first conveyor and lateral movement by said secondconveyor.

2. The apparatus defined by claim 1 wherein said second conveyor extendsfrom and is carried by said frame whereby the first and second conveyorsremain in brick transferring relationship.

3. The apparatus as defined in claim 1 wherein the sprockets mounted onsaid movable frame include first and second pairs of sprockets forguiding the first and second pairs of chains respectively from thespaced vertical planes of said one portion of the first vertical run toa common horizontal plane, additional pairs of sprockets around whichthe respective chains pass all rotatable about a common horizontal axislaterally spaced from said spaced vertical planes to define the lateralextent of the horizontal travel of said pairs of chains in said commonhorizontal plane. and further sprockets rotatable-about a common axisfor guiding said endless chains laterally from said additional sprocketsto a common vertical plane in the other por tion of said first verticalrun whereby the foldable pallets are carried in a horizontal planebetween said first and second portions of said one vertical run and discharge bricks onto the second conveyor as they pass around saidadditional pairs of sprockets.

4. The apparatus defined in claim 1 including platform means extendinghorizontally from and selectively vertically movable on the elongatedtower means independently of and conjointly with the second conveyormeans.

5. The apparatus defined in claim 4 wherein the platform means comprisesa series of horizontal, radially extending support members having acircular array of gratings thereon, the radially extending membershaving a telescoping function for forming a circular grating surface ofvariable diameter.

6. The apparatus defined in claim 4 wherein said second conveyor meansis vertically movable on said elon gated tower means below said platformmeans for relining the bottom of the vessel.

7. The apparatus defined in claim I wherein the second conveyorcomprises:

an endless belt of fixed length;

fixed roller means which define a loading point on the belt; and

movable roller means which are movable laterally to adjust the length ofan upper brick conveying surface of the belt and to prevent slack in thebelt.

8. The apparatus defined in claim I, including a rotating feed table forfeeding bricks to the charging end of the first conveyor means. adaptedto rotate about the tower at a speed of rotation greater than the speedof rotation of the tower.

9. The apparatus defined in claim 9 including:

speed-adjustable motor means for operating the first conveyor, secondconveyor and rotating feed table; and

means for transmitting motion from the motor means to the first conveyorsecond conveyor and rotating feed table so as to cause the firstconveyor. second conveyor and rotating feed table to move cooperativelyat speeds proportionate to any selected speed of the motor means.

10. The apparatus defined in claim 8 wherein the rotating feed tablecomprises a series of radial trays disposed at an angle above thehorizontal. interconnected in ring form. and having rollers thereinwhereby bricks on the trays are urged in a direction generally towardthe first conveyor means.

11. The apparatus defined in claim 10 including:

a feed conveyor positioned so as to feed bricks toward the rotating feedtable;

a control conveyor for controlling the transfer of bricks from the feedconveyor to the rotating feed table; and

sensing means associated with the rotating feed table. which sensingmeans detect the presence ofa brick on each radial tray when the tray isproximate the control coveyor. and prevent the transfer of a brick fromthe feed conveyor to the tray if a brick is present on the tray.

12. In an apparatus for lining the walls of a metallurgical vessel withrefractory bricks. which apparatus ineludes support means over the topopening of the vessel. elongated tower means suspended within the vesselfrom the suport means and rotatably movable thereon conveyor meanssupported by the toner and rotatably movable therewith for conveyingbricks vertically into the vessel and then horizontally toward the wallsof the vessel at variable heights and angular positions. a feed tablerotatable about the charging end of the conveyor means in the samedirection and at a proportionally faster rate than the rate of rotationof the tower and comprising a ring of trays each having a downwardly andradially inwardly inclined roller surface which urges bricks placedthereon toward the conveyor means. and a feed conveyor for chargingbricks on said rotating feed table. the improvement comprising:

control conveyor means between said feed conveyor and said rotating feedtable for controlling the transfer of bricks from the feed conveyor tothe ratating table, said control conveyor means including; control meansfor selectively retaining a brick on the control conveyor and for urginga brick from the control conveyor onto one of the feed table trays; and

sensing means responsive to the alignment of an empty feed table traywith said control conveyor for operating the control conveyor to urge abrick onto the empty tray.

13. The apparatus defined in claim l2 wherein said control meansincludes drive roller means, a pair of undriven rollers and actuatingmeans for raising and lowering the undriven rollers between a loweredposition in which a brick on the control conveyor is engaged by thedrive roller means and urged onto a feed table tray 10 and a raisedposition in which a brick is supported above and out of engagement withthe drive roller means, said actuating means being responsive to thefirst sensing means to move said undriven rollers to said loweredpositions when an empty tray is aligned with the control conveyor.

14. The apparatus defined in claim 13 wherein a brick is gravity fedfrom the feed conveyor onto the control conveyor when said undrivenrollers are moved to their lowered position and including second sensingmeans responsive to the transfer of a brick from the feed conveyor tothe control conveyor for operating the actuating means to move theundriven rollers to their raised position.

15. The apparatus defined in claim 12 wherein each feed table trayincludes gate means at the radially inward edge thereof to retain abrick thereon and means for displacing said gate when the associatedtray is aligned with the tower supported conveyor means such that thebrick is urged onto the tower supported conveyor means by the downwardlyand radially inwardly inclined roller surface of the tray.

16. The apparatus defined in claim [5 wherein said gate means includesmeans operative to render the sensing means inoperative to sense theabsence of a brick on the associated feed table tray when the gate hasbeen displaced to allow a brick to pass from the tray to the towersupported conveyor means thereby preventing the control conveyor fromtransferring a brick to the tray at the same time that a brick is beingtransferred from the tray to the tower supported conveyor means.

a n: a: a: a

1. In an apparatus for lining the walls of a metallurgical vessel withrefractory bricks which apparatus includes support means over the topopening of the vessel, elongated tower means suspended within the vesselfrom the support means and rotatably movable thereon, and first conveyormeans, in the tower and rotatably movable therewith, for conveyingbricks vertically within the vessel, the improvement comprising: asecond conveyor means having a laterally extending brick conveying uppersurface of adjustable length yertically movable on the tower means fortransporting bricks between the tower means and the walls of the vesselat variable heights and distances from the tower means; and wherein saidfirst conveyor means comprises: a plurality of sprockets; two pairs ofendless chains traveling in the same direction on a path defined by thesprockets, which path has two vertical runs between upper and lowersprockets rotatably mounted at fixed positions on the tower, one saidvertical run having a first portion in which one pair of chains travelsin a plane parallel to, and laterally disposed from, the plane of travelof the other pair, and a second vertical portion in which the pairs ofchains travel in the same plane, the other vertical run having the pairsof chains travel in the same plane throughout the run; a plurality offoldable pallets each of which is connected to both pairs of chains atspaced intervals along the chains, which pallets are horizontallysuspended between the chains during the first portion of said onevertical run, and are disposed in the same plane as the pairs of chainsduring the second portion of said one vertical run and throughout thesecond vertical run; and a frame having a plurality of sprocketsrotatably mounted and arranged thereon to guide one of said pairs ofchains along a substantially horizontal path between the two laterallydisplaced planes of the first portion and the common plane of the secondportion of said one vertical run which imparts substantial horizontalmovemenT to the foldable pallets as they pass from said first to secondportion of said one vertical run, said frame being vertically movable onthe tower to vary the respective lengths of said first and secondportions of said one run and to align the horizontally moving foldablepallets between said first and second portions in brick transferringrelationship with the second conveyor whereby bricks are conveyedbetween the exterior of the metallurgical vessel and the interior wallsthereof through vertical movement by said first conveyor and lateralmovement by said second conveyor.
 2. The apparatus defined by claim 1wherein said second conveyor extends from and is carried by said framewhereby the first and second conveyors remain in brick transferringrelationship.
 3. The apparatus as defined in claim 1 wherein thesprockets mounted on said movable frame include first and second pairsof sprockets for guiding the first and second pairs of chainsrespectively from the spaced vertical planes of said one portion of thefirst vertical run to a common horizontal plane, additional pairs ofsprockets around which the respective chains pass all rotatable about acommon horizontal axis laterally spaced from said spaced vertical planesto define the lateral extent of the horizontal travel of said pairs ofchains in said common horizontal plane, and further sprocketsrotatable-about a common axis for guiding said endless chains laterallyfrom said additional sprockets to a common vertical plane in the otherportion of said first vertical run whereby the foldable pallets arecarried in a horizontal plane between said first and second portions ofsaid one vertical run and discharge bricks onto the second conveyor asthey pass around said additional pairs of sprockets.
 4. The apparatusdefined in claim 1 including platform means extending horizontally fromand selectively vertically movable on the elongated tower meansindependently of and conjointly with the second conveyor means.
 5. Theapparatus defined in claim 4 wherein the platform means comprises aseries of horizontal, radially extending support members having acircular array of gratings thereon, the radially extending membershaving a telescoping function for forming a circular grating surface ofvariable diameter.
 6. The apparatus defined in claim 4 wherein saidsecond conveyor means is vertically movable on said elongated towermeans below said platform means for relining the bottom of the vessel.7. The apparatus defined in claim 1 wherein the second conveyorcomprises: an endless belt of fixed length; fixed roller means whichdefine a loading point on the belt; and movable roller means which aremovable laterally to adjust the length of an upper brick conveyingsurface of the belt and to prevent slack in the belt.
 8. The apparatusdefined in claim 1, including a rotating feed table for feeding bricksto the charging end of the first conveyor means, adapted to rotate aboutthe tower at a speed of rotation greater than the speed of rotation ofthe tower.
 9. The apparatus defined in claim 9 including:speed-adjustable motor means for operating the first conveyor, secondconveyor and rotating feed table; and means for transmitting motion fromthe motor means to the first conveyor, second conveyor and rotating feedtable so as to cause the first conveyor, second conveyor and rotatingfeed table to move co-operatively at speeds proportionate to anyselected speed of the motor means.
 10. The apparatus defined in claim 8wherein the rotating feed table comprises a series of radial traysdisposed at an angle above the horizontal, interconnected in ring form,and having rollers therein whereby bricks on the trays are urged in adirection generally toward the first conveyor means.
 11. The apparatusdefined in claim 10 including: a feed conveyor positioned so as to feedbricks toward the rotating feed table; a control conveyor forcontrolling the transfer of bricks frOm the feed conveyor to therotating feed table; and sensing means associated with the rotating feedtable, which sensing means detect the presence of a brick on each radialtray when the tray is proximate the control coveyor, and prevent thetransfer of a brick from the feed conveyor to the tray if a brick ispresent on the tray.
 12. In an apparatus for lining the walls of ametallurgical vessel with refractory bricks, which apparatus includessupport means over the top opening of the vessel, elongated tower meanssuspended within the vessel from the suport means and rotatably movablethereon, conveyor means supported by the tower and rotatably movabletherewith for conveying bricks vertically into the vessel and thenhorizontally toward the walls of the vessel at variable heights andangular positions, a feed table rotatable about the charging end of theconveyor means in the same direction and at a proportionally faster ratethan the rate of rotation of the tower and comprising a ring of trayseach having a downwardly and radially inwardly inclined roller surfacewhich urges bricks placed thereon toward the conveyor means, and a feedconveyor for charging bricks on said rotating feed table, theimprovement comprising: control conveyor means between said feedconveyor and said rotating feed table for controlling the transfer ofbricks from the feed conveyor to the rotating table, said controlconveyor means including; control means for selectively retaining abrick on the control conveyor and for urging a brick from the controlconveyor onto one of the feed table trays; and sensing means responsiveto the alignment of an empty feed table tray with said control conveyorfor operating the control conveyor to urge a brick onto the empty tray.13. The apparatus defined in claim 12 wherein said control meansincludes drive roller means, a pair of undriven rollers and actuatingmeans for raising and lowering the undriven rollers between a loweredposition in which a brick on the control conveyor is engaged by thedrive roller means and urged onto a feed table tray and a raisedposition in which a brick is supported above and out of engagement withthe drive roller means, said actuating means being responsive to thefirst sensing means to move said undriven rollers to said loweredpositions when an empty tray is aligned with the control conveyor. 14.The apparatus defined in claim 13 wherein a brick is gravity fed fromthe feed conveyor onto the control conveyor when said undriven rollersare moved to their lowered position and including second sensing meansresponsive to the transfer of a brick from the feed conveyor to thecontrol conveyor for operating the actuating means to move the undrivenrollers to their raised position.
 15. The apparatus defined in claim 12wherein each feed table tray includes gate means at the radially inwardedge thereof to retain a brick thereon and means for displacing saidgate when the associated tray is aligned with the tower supportedconveyor means such that the brick is urged onto the tower supportedconveyor means by the downwardly and radially inwardly inclined rollersurface of the tray.
 16. The apparatus defined in claim 15 wherein saidgate means includes means operative to render the sensing meansinoperative to sense the absence of a brick on the associated feed tabletray when the gate has been displaced to allow a brick to pass from thetray to the tower supported conveyor means thereby preventing thecontrol conveyor from transferring a brick to the tray at the same timethat a brick is being transferred from the tray to the tower supportedconveyor means.